Continuity mistake: When Prue leaves Buckland's, she's wearing a red tank top, but when she arrives at Camp Skylark, her shirt is different, both in style and color. She can't have stopped to change, because it's mentioned she left the auction house and headed directly to the camp. (00:07:00 - 00:09:20)
Continuity mistake: After Prue and Phoebe send contagious Piper back up to bed, it cuts to three consecutive shots of buses arriving at camp. In the first shot, the bus license plate is white with the number "2IAB345" and we see markings on the bus as the counselor exits. The second closer shot shows two kids exiting the bus. Then in the third wideshot, with those same two kids beside the door, the license plate is now blue with the number "876QPD" and we see the same markings on the bus as in the first shot, so we know it's the same bus. (00:22:05)
Continuity mistake: As soon as the water demon enters Sam, we can see that Prue's hair is completely dry. Then when she flips the switch to electrocute Sam to kill the water demon, her hair goes from dry to wet without ever coming into contact with any water. (00:36:25)
